Perhaps you should try some spelling variations:
thieu sach » chieu sach, hieu cach, theo sach
thien hach » thien thanh, hien hanh
hanh trung » thanh trung, hanh trang, manh trung
nhung cong » dung cong, thong cong, hang cong
trung cua » truong cua, trung tuan, trung cap
cua nhung » va nhung
cong tang » cong thang, cong tan, cong lang
tang van » dang van, hoang van, trong van

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((thieu sach) or (thien hach)) - hanh trung cua nhung cong tang van ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sach) OR (thien hach)) - hanh trung cua nhung cong tang van ban.
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sach) or (thien hach)) - hanh trung cua nhung cong tang van ban*.